Mmm, it owned.
It wasn't nearly as fun as a small venue, which I expected. The entire performance seemed very rigid, and practiced, so when something odd happened (a shirt on the monitor, a glowstick on the stage, etc) they totally ignored it. And the stuff they say between songs sounds so fill-in-the-blank-style, "It's great to be here in *checks back of guitar* Winnipeg!"
But other than that, the music itself was awesome. The bands were, in the order they played:
Thine Eyes Bleed, Mastodon, Children of Bodom, Lamb of God, Slayer
And all I can say is that in terms of goodness, it was something like:
Children of Bodom > * > Mastodon
The other three, I can't really compare.
But it really seemed like Slayer didn't fit in with the other bands. Slayer is way 80's, and the rest of them are newer, and of a totally different style/sound.
Also, Slayer didn't do the scream at the beginning of Angel of Death. I was upset about that.